Final answer:
The Battle of Waterloo ended Napoleon's reign, sparked nationalism, led to the unification of territories such as Italy, and significantly altered the European geopolitical balance, allowing Great Britain to emerge as the world's leading superpower.
Step-by-step explanation:
The Battle of Waterloo had a profound impact on the world. It marked the end of Napoleon's rule and brought significant changes to the European geopolitical landscape. The correct answer is B) The defeat of Napoleon promoted nationalism in Italy and the unification of the territory. This is because the Napoleonic wars, while autocratic and marred by plundering, inadvertently spread ideas of a more egalitarian social system and incited a strong sense of nationalism among conquered populations like Italians, Germans, and Spaniards.
Following the battle, the Congress of Vienna sought to redefine European borders, balance power, and maintain peace. This restructuring of the continent reinforced and created new nations, setting the stage for future Moves towards national unification as residents began to identify more with nationalities rather than monarchical rule. The defeat also led to Britain establishing a period of notable global dominance, known as Pax Britannica, making Great Britain the world's predominant superpower.